The EU response was part of a growing diplomatic backlash over Iran's crackdown on opposition protests as world powers questioned the validity of the election that gave the combative Ahmadinejad another four years in power.

German Foreign Minister Frank-Walter Steinmeier described the action of the security forces as "completely unacceptable."

British Foreign Secretary David Miliband decried what he said appeared to be state violence against the Iranian people.

"The very serious doubts that have been raised about the free and fair nature of the election counting process are obviously of major concern to many people in Iran," Miliband said as he arrived for the Luxembourg talks.

"I think that in the very short term people will continue to focus on what seems to be state violence against its own people in Tehran and elsewhere," he added.

While stressing their concern, the foreign ministers made it clear that they want international talks on Iran's nuclear programme to resume.

"It remains a priority for the EU that Iran engages with the concerns of the world community, above all on the issue of Iran's nuclear programme," their statement said.

EU foreign policy chief Javier Solana, who represents six major powers -- Britain, China, France, Germany, Russia and the United States -- in discussions with Tehran, was clear that the process should continue.

"We would like to get engaged and continue to be engaged with the people of Iran, and the leaders of Iran.

"I hope a meeting will be possible and as soon as the government is in place," he stressed, seeking the first such talks since last September.

Western powers fear that Iran wants to build an atomic bomb, but Tehran insists it merely aims to produce civilian nuclear energy.

Analysts suggest that Ahmadinejad's re-election could further isolate Iran which is under three sets of UN sanctions over its nuclear programme.

"We continue to await an Iranian answer to the very generous proposals that were made by the international community in respect to the Iranian nuclear programme," said Miliband, referring to political and trade incentives.

"Our prime concern is not who governs Iran, our prime concern is how Iran engages with the international community," he added.

"The international community is offering respect to Iran, what it wants is responsibility in return and we have not yet seen that from the regime," he insisted.